Irondequoit Water Hardness & Quality Report (2026)

Irondequoit, NY, receives its drinking water primarily from the City of Rochester's system, which has supplied residents since 1876 from Hemlock and Canadice Lakes. These reservoirs are supplemented by Lake Ontario water purchased from the Monroe County Water Authority (MCWA), treated at the Shoremont Treatment Plant on Dewey Avenue. Treated water from the Hemlock Filtration Plant travels via century-old pipelines to city reservoirs for storage and re-disinfection before distribution through over 500 miles of mains serving Monroe County communities including Irondequoit. The full service area covers the Rochester metro region under Rochester Water and MCWA oversight.

The supply lies within the Genesee River watershed (HUC 04140101) for the lakes and the broader Lake Ontario basin. Hemlock and Canadice Lakes are fed by streams draining Devonian shale and sandstone formations with thin limestone interbeds, while Lake Ontario integrates inflows from diverse northern geology including igneous and metamorphic rocks. No dedicated aquifer is tapped; surface water dominates. This glacial lake setting yields moderately mineralised water, as limited rock-water interaction in forested, low-carbonate uplands restricts ion leaching compared to limestone-dominated karst regions.

Soft water produces negligible scale buildup, sparing appliances like water heaters, dishwashers, and coffee makers from mineral deposits. Soap lathers easily without excess, and laundry detergents perform efficiently with minimal residue. No softener is needed or recommended. Water is fluoridated to ~0.7 ppm for dental health and treated with disinfection including re-disinfection post-reservoir. Bromodichloromethane has been detected above health guidelines; school testing in West Irondequoit revealed lead above 5 ppb in some outlets as of April 2025, prompting filtration and plumbing fixes per NYSDOH rules. Treatment includes filtration, disinfection, and fluoridation.